Refrigeration system



April 4, 1950 v. c. PATTERSON 2,503,212

REFRIGERATION SYSTEM Filed June 16, 1948 Patented Apr. 4, 1950REFRIGERATION SYSTEM Velt Cowan Patterson, York, Pa., assignor to V. 0.

Patterson & Associates, Inc., York, Pa., a corporation of PennsylvaniaApplication June 16, 1948, Serial No. 33,375

10 Claims. 1

ous floors or rooms of multi-story buildings a,

complete system may be installed on each floor, or a central system maybe installed on one floor to furnish refrigeration to several or allfloors. Where a complete system is provided on each floor, there is anexpensive duplication of controls, pumps, condensers, storage tanks, andthe like. Where a central system is provided on one floor, usually thelower floor, known systems are not completely satisfactory because ofthe problems which arise in distributing refrigerants to different floorlevels at different heads and for variable demands. The recirculatingsystem disclosed hereinafter eliminates many of the problems ofduplicate systems and the distribution problems of central systems.

It is an object of this invention to provide an efficient centralrefrigeration system for multistory buildings in which each floor levelis furnished with adequate refrigeration regardless of the refrigerationdemand on other floor levels of the building.

It is another object of this invention to provide a centralrefrigeration system for multi-story buildings for use with arecirculated liquid ammonia type of refrigerant.

It is another object of this invention to rovide a liquid recirculatingrefrigeration system for multi-story buildings which facilitatesindividual temperature control of the refrigeration furnished to eachfloor or level.

It is another object of this invention to provide a refrigeration systemfor multi-story buildings in which the distribution apparatus on eachlevel may be conveniently isolated from the space or spaces to be cooledon that level.

It is a further object of this invention to provide a double pumpingliquid recirculating refrigeration system for multi-story buildings.

It is a still further object of this invention to provide arefrigeration system for multi-story buildings which provides anadequate distribution of liquid ammonia to each level to berefrigerated.

. Other objects, advantages and features of the present invention willbecome readily apparent from the following description of the embodimentillustrated in the accompanying drawings wherein:

Figure 1 is a diagrammatic illustration of a refrigeration system for asix-story building.

Figure 2 is a diagrammatic partial plan view of the preferred locationof refrigeration apparatus provided on each of the upper levels of thebuilding shown in Figure 1.

Referring to the drawings, the exemplary embodiment of the invention isshown applied to a cold storage ware house having spaces ill on fivedifferent levels which are to be refrigerated. The apparatus provided onthe first or basement level II includes a master surge drum l2 forcontaining liquid and gaseous ammonia as a refrigerant medium. The topof the master surge drum [2 is connected by a conduit I3 to acompressorI4 which in turn is connected by conduit l5 to a condenser It. Thecondenser I6 is connected to a receiver I! which is connected by conduit[8 back to the master surge drum l2. Suitable controls such as a floatswitch l9 and an electromagnetic valve 20, of conventional character,may be provided to permit liquified ammonia to flow from the receiver I!through high pressure conduit [8 to the master surge drum I2 as fast asit accumulates in the receiver or when the liquid level in receiver llrises above a selected point. Visual or other forms of gauges may beprovided to indicate the liquid level in the master surge drum and inthe receiver [1. The lower portion of the master surge drum I2 isconnected by a conduit 2! to the inlet of a high head ammonia pump 22.The pump 22 should be of sufiicient capacity to pump to the top of thebuilding about five times as much liquid ammonia as is estimated to berequired to refrigerate all of the spaces Ill.

The apparatus on each floor level of the building to be refrigerated maybe identical on each level, and includes a surge drum 25, a low headammonia pump 26 driven by a motor M, a distribution valve 21, a coolingcoil or coils 28, and a thermostat 29. The coils 28 and the thermostat29 are located in the space I!) to be cooled. The pump 28 pumps liquidammonia from the surge drum 25 through the distribution valve 21 intothe cooling coil 28. Space temperature is controlled by the thermostat29 which starts the pump 26 when more cooling is required and stops thepump 26 when the space temperature is low enough. The thermostats 29may, of course, be adjustable and of conventional construction.

A circulation pipe 30 for liquid ammonia extends from the outlet of pump22 to the top of the top surge drum 25. The return pipe 3| extends fromthe upper portion of the upper surge drum downward to the upper portionof the master surge drum l2. Each surge drum 25 is connected to thereturn pipe 3| at two levels by valved connections-32 and 33. Valves34,'nor-. mally closedyare provided in the return pipe 3ibetween theentry points of each pair of connections 32 and 33.

During normal operation of the systemrdescribed above, valves 34 inreturn line 3| are all closed and valves 32 and 33areall opens Liquidammonia is pumped by the'pump 22 through* conduit into the top of thetop surge drum 25. Liquid ammonia collects in the bOt/tOm'pOItiOnOfU thetop surge drum 25 and excess liquid ammonia flows through open valve 33into the return pipe 3|. Said excess then enters the top of the nextlower-surgedrum 2 5 through a connection 32'--and= maintains aliquid-"lever in the lowerportion of l the drum: Again 'excessliquidre-enters the return pipe 3| through connection 33 and passes downwardto'the'nextlower -surge drum 25. Excessliquid ammonia from-thelower-most surge drum 25 enters the return' pipe 3l through a connection33- 'and is returned -'to the upper portionof" th'e'master-surge drumiZa Thus each surge drum 25 is maintained -with' an ample'supplyofliquid ammonia in its lower' portion. At each level of the building;the low head ammonia pump 26" withdraws liquid-ammonia from the bottomof the-adjacent 'surge drum-==25 and passesit through thedistributionvalve TI-into thecooling coil28. A portion ofthe'ammonia in-coil 28 isexpanded to a gaseous statein 'cooling'the space ID'; andmixed gas-andliquid-from the coil- 28 is returned tothe top-of thesurge drum25'through conneotion-%"- Gaseous ammonia flows from the and eventually-into the upper portion of'=the* master surgedrum l2; 1 Gaseous ammoniais continually drawn off 1 the top of the master surge drum 'throughconduit I 13- to the compressor -14 where it is compressed-and deliveredby conduit l5 to'the condenser 16. The compressed gasis' liquefied-inthe condenser "I 6 and thencollected inthe receiver 11" forautomaticreturn asliquid ammonia to the master surge druml2ron-recirculation.

Where it-is-estimated that each of the fivespaces [0 to be refrigeratedmay require about: one'gallon of liquid'ammonia per minute,'='thehi'ghhead liquid ammonia pump 22- should be of sufficient capacity"to'-circulate" about 'twenty five gallons per minute of liquid ammoniaupward" through supply pipe 30 into" the top'sur-ge drum 255' Such acapacity provides thatthere will al'-=* ways'be ample liquid ammonia inthe lower por tion-of each of the five surge drums 25;

The surge drum 25 andoirculatin'g pump -26 on each'level of themulti-story building -may-beconveniently'placed in a corner-room asshown in Figure 2. The'outlet from each pump-26 may be connected to aheader 4l*}'-and each of several cooling coils 28' on that level-maybeconnected- 75 to the header 4| by distribution valves 21. A similarheader, not shown, may be used to collect the gaseous and liquid returnfrom each coil 28 for passage through conduit 35 back into the surgedrum 25. The location of the apparatus at each level in a separate room40 provides easy access to the equipment for adjustment and repairs whennecessary. The space 40 may be provided with windows 42 to allow crossventilation of the apparatus in room 40 when required.

Whenever the apparatus on a given level requires repair or when a spaceIt] is to be temporarily without refrigeration, the valved connections32and 33 at that level may be closed after opening the adjacent valve 34to permit the refrigerant flow in return pipe 3| to by-pass thatparticulairleveL: At each level, an emergency connection 43 may extendfrom the supply pipe 30 to the'header-fl orthe distribution valve 21 toprovide-for supplying liquid ammonia direct from the supply'line 30tothe cooling coil 28 in the event -that=pump23 is out of operation forrepair. However, valves 44 in the conduits 43 are normallymaintainedclosed. There may also be provided at each level, a safety connection 45extending-from-the=coils'28 to-a conduit 46 which entersthe return: line3| at-a low-level." Each safety connection is normally closed;preferably by a conventional bursting disc 4! which will rupture if therefrigerant pressure in the cooling coil: 23' ever should-exceed the'pressure in the return line 3l by--about one--hundred. and fifty poundsper squareinch There: also may be provided a small diameterr valvedconduit 48 extendingfrom:the' compressed gasconcluit I 5 upwards to theoutlet of each 0001- ing coil mi ror conveying-hot gases ior useinzdefrosting thecoils-28"svhen requiredu The valves 49 should -be ke'ptolosed'except during=a defrost-- ing operation. The: master surge drum:l 2'- may be' provided with a drainvaIVe-WSand a pressurerelie'fi'valve"5l 'as is-well known 'in the 'art; A valved conneotion 52may alsobe provided be tween -'tl1e bottom ofoeach surge'drum 25 and thereturn line: 3 I ioi draining' surge: drum: 2 5: of 1 liquid ammonia oraccumulated oil.=l=

lt will be apparent from the above descriptionof the system illustrateddiagrammatically in the :drawings. that 1 the system provides: for.individual space temperature controlby individual. thermostats 292f'0rcontrblling thezlowhead liquid ammonia pumps 26. The volumeoiliquidammoz-l nia in' circulation underhi'gh head is :onlya smallfraction of the total liquid ammonia :in :circulaa: tion; and thus pumpwear; pump cost; and. power: requirements are minimizedu Thensystempro:-. vides for an emergency 'feed of liquidl ammonia totll'e'coolingcoils '28' th'rough conduits43'; iShould. a pump-23 be take'n'outof-ioperationrfor any reae; song-'thezemergency. liner43' can .be arseduntil the; pump is repaired. Individual;space temperatures; arecontrolled t'vith a very minimum; of. controls and no -liquid -levelcontrols Jane: requiredvon any. level: except the -fioa t :'switch I 9%on :receiver :4 1'.

- With thesystem herein described,:the-volume: of.

ammonia charge is considerably 'less than when individual 1refrigeration: systems are provided on each 'level; I The use 'of thedouble: pumping res? circulatingarrangement *makes proper adjustment ofthe: distribution valves 2'! much easier than "where: a singlelpumpoent-ral: system'xis Kin-f1 stalled" With' the'zsystemishown;nozhigh pressure" conduits" are required to iexten'd upwards: throughthe building. The only high pressure liquid. ammoniaconduitistheJ-ineLBwxtending fromcthe receiver ll to the master surge drum I: atthe lower level. Another advantage of the system shown is the fact thatthe surge drum, low head pump and distribution headers at each level maybe placed in a protected space separate from the refrigerated space I0,thereby providing for easy ventilation and access.

This invention contemplates the use of various other form of pumps,surge drums, control valves,

:etc.,- as it will be readily apparent to the skilled .ings comprisingin combination; refrigerant liquefying apparatus on a lower floorincluding a compressor, a condenser, a receiver, and a master surge drumfor containing both gaseous and liquid refrigerant; space coolingapparatus on each of several upper floors including a surge drum, arefrigerant evaporator, and a pump for pumping refrigerant from saidsurge drum to said evaporator; a pump on said lower floor for pumpingliquid refrigerant from said master surge drum into said surge drum onthe uppermost floor to be cooled, conduits connecting each of said surgedrums to the surge drum on the next lower floor, and a conduitconnecting the lowermost surge drum to said master surge drum.

2. A refrigeration system for multi-story buildings comprising incombination; refrigerant liquefying apparatus on a lower floor includinga compressor, .a condenser, a receiver, and a master surge drum forcontaining both gaseous and liquid refrigerant; space cooling apparatuson each of several upper floors including a surge drum, an evaporatorcoil, a pump for pumping refrigerant from said surge drum to said coil,and thermostatic means in said space to be cooled controlling said pump;a high head pump on said lower floor for circulating liquid refrigerantfrom said master surge drum into said surge drum on the uppermost floorto be cooled, conduits connecting each of said upper floor surge drumsto the surge drum on the next lower floor, and a conduit connecting thelowermost surge drum to said master surge drum.

3. A refrigeration system for multi-story buildings comprising incombination; refrigerant liquefying apparatus on a lower floor includinga ccmpressor, a condenser, a receiver, a master surge drum forcontaining both gaseous and liquid refrigerant, and a valved conduit forcontrolling the flow of liquid refrigerant from said receiver to saidmaster surge drum; space cooling apparatus on each of several upperfloors of said building including a surge drum, an evaporator coil and apump for pumping liquid refrigerant from said surge drum to said coil; apump on said lower floor for pumping liquid refrigerant from said mastersurge drum into the surge drum on the, uppermost floor to be cooled, andconduits connecting each of said upper floor surge drums to the surgedrum on the next lower floor and connecting the lowermost surge drum tosaid master surge drum.

4. A refrigeration system for multi-story buildings comprising incombination; refrigerant liquefying apparatus and a master surge drum ona lower floor; space cooling apparatus on each of several upper floorsincluding a surge drum, an evaporator coil, a pump for pumping liquidrefrigerant from said surge drum to said coil, and a return conduit fromsaid coil to said surge drum; a continuous pump on said lower floor forcirculating liquid refrigerant from said master surge drum to theuppermost surge drum, a return conduit connecting said surge drums inseries and connecting the lowermost surge drum to said master surgedrum.

5. A refrigeration system for multi-story buildings comprising incombination; refrigerant lique- 'fying apparatus and a master surge drumon a lower floor; space cooling apparatus on each of several upperfloors including a surge drum, an evaporator coil, a pump for pumpingliquid refrigerant from said surge drum to said coil, and a returnconduit from said coil to said surge drum; a pump on said lower floorfor circulating liquid refrigerant from said master surge drum to thesurge drum on the uppermost floor to be cooled, a return conduitconnecting said surge drums in series and connecting the lowermost surgedrum to said master surge drum, and valved .by-pass connections in saidreturn conduit for passing circulating refrigerant by any of said upper.floor surge drums.

6. A refrigeration system for multi-story build ings comprising incombination: refrigerant liquefying apparatus and a master surge drum ona lower floor; said liquefying apparatus being connected to said mastersurge drum for liquefying gaseous refrigerant and returning liquidrefrigerant to said drum; space cooling apparatus on each of severalupper floors including a surge drum, an evaporator coil, and a pump forpumping liquid refrigerant from said surge drum to said coil; a highhead pump on said lower floor connected to said master surge drum, 2.supply conduit extending from said pump to the topof the uppermost surgedrum, a return conduit connecting said surge drums in series andconnecting the lowermost surge drum to said master surge drum, andvalved conduits extending from said supply conduit direct to each ofsaid evaporator coils for by-passing said surge drum and pump on anyfloor.

7. A refrigeration system for multi-story buildings comprising incombination; refrigerant liquefying apparatus and a master surge drum ona lower floor; said liquefying apparatus being connected to said mastersurge drum for liquefying gaseous refrigerant and returning liquidrefrigerant to said drum; space cooling apparatus on each of severalupper floors including a surge drum, a pump, and an evaporator coil; apump on said lower floor connected to said master surge drum, a supplyconduit extending from said pump on said lower floor to the uppermostsurge drum, a return conduit connecting said surge drums in series andconnecting the lowermost surge drum to said master surge drum, aseparate return conduit extending from the uppermost floor to be cooledinto said first-mentioned return conduit at a point above said mastersurge drum, and pressure relief connection between the outlets of saidevaporator coils and said separate return conduit.

8. A refrigeration system for multi-story buildings comprising incombination; refrigerant liquefying apparatus and a master surge drum ona lower floor; said liquefying apparatus being connected to said mastersurge drum for liquefying gaseous refrigerant and returning liquidrefrigerant to said drum; apparatus on each of several upper floorsconfined in a closed space on said floor and including a surge drum anda pump, an evaporator coil within a space to be cooled on said floorconnected to said pump and said surge drum; a high head ump on saidlower floor connected to said master surge drum, a supply conduitextending from said high head pumpto the uppermost surge drum, a returnconduit connecting said surge drums in series and connecting thelowermost surge drum to said master surge drum.

9. A refrigeration system for multi-story buildings comprising incombination, refrigerant liquefying apparatus on a lower floor includinga compressor, a condenser, a receiver, and a master surge drum forcontaining both gaseous and liquid refrigerant; space cooling apparatuson each of several upper floors including a surge drum, a refrigerantevaporator coil, and a pump for pumping liquid refrigerant from saidsurge drum to said evaporator coil; a pump on said lower floor connectedto said master surge drum for pumping liquid refrigerant to theuppermost surge drum, conduits connecting said upper floor surge drumsin series for returning liquid and gaseous refrigerant to said mastersurge drum, and a hot gas line extending from said refrigerantcompressor to each of said evaporator coils for use in defrosting saidcoils.

10. Arefrigeration system for multi-story buildings comprising incombination; ammonia liquefying apparatus on a lower floor including acompressor, a condenser, a receiver, and a master surge drum, saidcompressor being connected to the top of said master surge drum to drawgaseous ammonia therefrom and said receiver being connected to saidmaster surge drum to return liquid ammonia thereto; space coolingapparatus on each of several upper floors of said building including asurge drum, an evaporator coil, and a pump for pumping liquid ammoniafrom the lower portion of said surge drum into said evaporator coil, theoutlet of said coil being connected to the upper portion of said surgedrum; a high head pump on said lower floor connected to said mastersurge drum for circulating liquid ammonia from said master surge drum tothe upper portion of the uppermost surge drum, a conduit connecting thecentral portion of said uppermost surge drum to the upper portion of thesurge drum on the next lower floor, another conduit connecting thecentral portion of said last-mentioned surge drum with the top portionof a still lower surge drum, the lowermost surge drum being connected tothe upper portion oi said master surge drum for returning gaseousammonia and excess liquid ammonia thereto for liquefaction andrecirculation.

VELT COWAN PATTERSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,796,007 Dickey Mar. 10, 19311,891,231 Hull Dec. 20, 1932

